So I was planing on doing a carbed 350 swap but never got it to run after everything was swapped. Now I have a chance to grab a truck 350 tbi and a 98 vortec 350 I'm kinda torn between the 2 motors. Ok now here's where I Need you guys to help me out if I go carbed vortec what all will I need to safely swap to carb I read that I have to change timing chain cover and bypass coolent valve as well as flywheel ,starter and need a custom exhaust ran and will my old 305 serpintine drive work with vortec motor.If I get tbi 350 will everything from truck including engine harness and tbi work I cut my 305 tbi engine harness with first swap but have everything from old motor but dizzy and a few hoses so will the truck engine harness work in place of old engine harness. Sorry about grammar. Lol

 

If I choose to get tbi I wanna keep tbi injection motor is out of 92 silverado and can a carb car be a good daily driver.

 

Yes carb cars can 1000% be a good driver. I mean really think about this one for a second. People drove cars every day back in the 1950's, 60's, 70's etc before fuel injection.

The car, the engine does not care how it gets the air/fuel mixture, all it knows is it gets the correct amount of air and fuel... If the carb is tuned right and dialed in right it WILL get just as good of fuel mileage as EFI, it WII be just as reliably as fuel injection.

I have a carbed 390 HP V8 S10 with 3 speed auto that gets 17 mpg... If I had an overdrive transmission it would get 20+ mpg.

I would pick the vortec engine for a few reasons.
Vortec heads flows great
92 silverado 350 TBI heads are swirl port garbage
Vortec engine is a factory roller cam engine
92 silverado has a hyd. flat tappet cam.

I don't understand the custom exhaust part.. Same exhaust that works on the 92 TBI engine will work on the Vortec engine.

Yes your stock 305 serpentine drive will work with vortec engine.

 

Truck 350 TBI or truck 350 Vortec.

Is there even a question here???

Seriously, the TBI engine should only be considered as a shortblock to put Vortec heads on. But if you can get a 350 with Vortec heads and roller cam setup already, why even consider the TBI engine? Even if you plan on putting TBI back on it, the Vortec is still the superior choice.

 

I decided to go with the vortec 350 I was told that my old exhaust would not bolt to the vortecs manifold. What type of hp numbers will I see with thes combo of parts air gap assault intake demon 625 carb roller rockers and I'm keeping my 305 exhaust no cats y pipe 1 in 2 out flowmaster and is it really nessasary to run a old stlye timing cover and coolent bypass valve.

 

The stock exhaust is a major choke point. Really don't ask about HP increse when you still have stock manifolds and Y pipe.

Those are the 1st 2 things you should swap out when looking for performance gains.

I seen stock exhaust kill off as much as 60 HP on modded engines.

The vortec 350 makes 255 HP stock, but it's intake and exhaust manifolds are restrictions. With aftermarket intake and headers they can make up to 300 HP with out doing much else to them.

Easy to get 350 HP from the vortec engine with better intake, headers, cam swap, and valve spring swap

 

The Vortec heads flow great, but their benefit is lost if you aren't using a cam that takes advantage of their design. They flow best at mid-lift, so you'll want a cam that gets the valves off their seats fast and closes them late. Many folks have used (somewhat) radical flat-tappet cams to do this, but a roller cam is inherently designed to do this while also allowing you to use modern oil. You will be best served by retaining the Vortec engine's lifters and finding a higher lift and longer duration cam (270 advertised is a good "zone"). To run any lift higher than .420" you will need to either machine the heads for new springs (easy to ruin the head) or use LS beehive springs (much safer and cheaper in the long run.) There are many write-ups on this combination making 400+ HP.